This application relates to capillary flow assays.
Various lateral flow assay techniques can be used to determine the presence or absence of analytes in a sample. For example, lateral flow assay can be used to detect the presence of drugs in bodily fluids such as blood, urine, saliva and other liquid samples. A lateral flow assay device includes a single continuous solid piece of absorbent material that allows analytes to move from one end of the material to the other end once a sample containing the analytes is in contact with the one end of the material.